Sweet orange tree named ‘N7-3’

ABSTRACT

A new Valencia-derived sweet orange tree particularly distinguished by trees that bear virtually seedless (an occasional seed can be found) ‘Valencia’ type sweet orange fruit, fruit that ripens slightly later than standard ‘Valencia’ trees, good fruit quality which holds into June and fruit having good juice quality when no other commercial  citrus  is available in Florida, is disclosed.

Genus and species: Citrus sinensis L. Osbeck.

Variety denomination: ‘N7-3’.

BACKGROUND OF THE NEW PLANT

The invention relates to a new and distinct variety of sweet orangetree, Citrus sinensis L. Osbeck, named ‘N7-3’. ‘N7-3’ is a moderatelyvigorous tree that produces standard ‘Valencia’ type sweet orange fruitbut unlike standard ‘Valencia’ clones, the fruit of ‘N7-3’ is virtuallyseedless (an occasional seed can be found) and exhibits a fruitmaturation date later (2 to 8 weeks) than standard ‘Valencia’ trees. InFlorida, the fruit quality of ‘N7-3’ can generally be harvested frommid-March through June, depending on environmental conditions. Juicequality from fruit of ‘N7-3’ is equivalent to that of standard‘Valencia’, the highest quality juice from oranges currently available.‘N7-3’ is a dual-use, late-season cultivar that can be used for freshmarket or processing.

‘N7-3’ originated as a ‘Valencia’ somaclonal tree regenerated fromprotoplasts isolated from an embryogenic suspension culture of standard‘Valencia’ (Citrus sinensis L. Osbeck) in 1989. For the methodology,please see Grosser, J. W. and F. G. J. Gmitter (1990). Protoplast fusionand citrus improvement. Pp. 339-374. In: Janick, J. (Ed.). PlantBreeding Reviews. Timber Press, Inc., Portland, Oreg., USA. The originaltree was grafted to ‘Swingle’ citrumelo rootstock and was planted inLake Alfred, Fla. in 1991. ‘N7-3’ is a true seedless ‘Valencia’ sweetorange with an altered maturity date that allows for an extended harvestbeyond the time when any quality commercial citrus is available inFlorida.

‘N7-3’ has been subsequently asexually propagated by conventionalbud-grafting onto ‘Swingle’ and ‘Carrizo’ rootstocks. The presentinvention has been found to retain its distinctive characteristicsthrough successive asexual propagations.

Plant Breeder's Rights for this cultivar have not been applied for.‘N7-3’ has not been made publicly available or sold more than one yearprior to the filing of this application.

SUMMARY OF THE INVENTION

‘N7-3’ is a new and distinct variety of sweet orange tree which bearsseedless fruit that ripens around mid-March and holds quality throughJune during most years. ‘N7-3’ trees usually bloom between early to lateMarch in central Florida, depending on environmental conditions. ‘N7-3’trees have an upright plant habit and of moderate vigor, typical of‘Valencia’ sweet orange trees.

‘N7-3’ trees bear fruit that is typical of ‘Valencia’ trees but ‘N7-3’ripens slightly later (usually mid-March) and hold good fruit qualitywell into June in Florida. Juice quality of ‘N7-3’ fruit is typical of‘Valencia’ fruit in sugar and acid content, color and flavor. ‘N7-3’fruit are juicy, difficult to peel and seedless, with an occasionalseed, unlike standard ‘Valencia’ fruit, which averages 3.9 seeds perfruit. Replicated trials (both second generation and top-worked thirdgeneration trees), to determine yield were destroyed by the Floridastate-run canker eradication program. Based on observations, ‘N7-3’appears to yield slightly less fruit than standard ‘Valencia’ trees, butis adequate for commercial harvesting.

The following are the most outstanding and distinguishingcharacteristics of this new cultivar when grown under normalhorticultural practices in Florida.

-   -   1. Trees that bear seedless ‘Valencia’ type sweet orange fruit;    -   2. Fruit that ripens slightly later than standard ‘Valencia’        trees;    -   3. Good fruit quality which holds into June; and    -   4. Fruit having good juice quality when no other commercial        citrus is available in Florida.

DESCRIPTION OF THE PHOTOGRAPHS

This new sweet orange plant is illustrated by the accompanyingphotographs which show the plant's form, foliage and fruit. The colorsshown are as true as can be reasonably obtained by conventionalphotographic procedures. The tree photographs were taken in January2009, and the photo of the fruit was taken in March 2008.

FIG. 1 shows a section of the original ‘N7-3’ tree on ‘Swingle’rootstock taken prior to harvest in 2009.

FIG. 2 shows fruit cropping on a 5-year old ‘N7-3’ tree on ‘Carrizo’citrange rootstock.

FIG. 3 shows a close-up of the mature fruit, a cross-sectional view ofthe fruit and a longitudinal sectional view of the fruit.

DESCRIPTION OF THE NEW CULTIVAR

The following detailed description defines the characteristics of‘N7-3’. The present botanical description is that of the variety grownat the University of Florida Citrus Research and Education Center inLake Alfred, Fla. in 2007 and 2008 on ‘Swingle’ citrumelo rootstock(original tree, 18 years old) or ‘Carrizo’ citrange rootstock (secondgeneration trees, 5 years old). The colors (except those in commonterms) are described from RHS Colour Chart published by The RoyalHorticultural Society in London, in association with the Flower Councilof Holland (2001).

DETAILED BOTANICAL DESCRIPTION

-   Classification:    -   -   Botanical.—Citrus sinensis L. Osbeck.        -   Common name.—Sweet orange.        -   Parentage.—Somaclonal tree regenerated from protoplasts            isolated from an embryogenic suspension of tissue culture of            standard ‘Valencia’ (unpatented).-   Tree:    -   -   Ploidy.—Diploid.        -   Form.—Obloid, typical of ‘Valencia’ sweet orange.        -   Vigor.—Moderate; typical of ‘Valencia’ sweet orange.        -   Size.—Typical of ‘Valencia’ type trees; depends on the            rootstock used; height of mature tree on ‘Swingle’ citrumelo            rootstock is approximately 4.4 m.        -   Trunk diameter (on ‘Swingle’ citrumelo rootstock).—18.0 cm.        -   Bark color.—Between RHS 199 (Greyed-brown) to RHS N199A            (Greyed-brown).        -   Density.—Typical of ‘Valencia’ sweet orange.        -   Thorn length.—1.5 cm±0.6 cm.        -   Thorn color.—Between RHS 199 (Greyed-brown) to RHS N199A            (Greyed-brown), depending on the age of the bark.        -   Thorn shape.—Straight.-   Leaves:    -   -   Type and shape.—Simple and elliptical.        -   Apex.—Acuminate.        -   Base.—Obtuse.        -   Margin.—Entire margin is moderately articulate.        -   Length.—7.67 cm.        -   Width.—4.61 cm.        -   Adaxial color.—RHS 137A (Green).        -   Abaxial color.—RHS 144A (Yellow-green).        -   Texture.—Smooth.        -   Petiole.—Appearance and attachment: Articulate and            brevipetiolate. Length: 1.32 cm. Width: 0.32 cm. Color: RHS            137A (Green).-   Flowers:    -   -   Blooming period in central Florida.—Early to late March.        -   Petals.—Quantity (per flower): 3.7±0.5 to 4.6±0.5. Length:            1.35 cm±0.20 cm to 1.78 cm±0.26 cm. Width: 0.6 cm±0.1 cm to            0.66 cm±0.12 cm. Color: RHS 155D (White).-   Fruit:    -   -   Time of maturity.—About mid-March in central Florida.        -   Shape.—Spheroid, with some that are slightly oval in shape.        -   Apex.—Rounded.        -   Base.—Convex.        -   Fruit (flesh) color.—RHS N25C (Orange).        -   Height.—7.5 cm±3.6 cm.        -   Width.—7.3 cm±4.2 cm.        -   Fruit height to width ratio.—Approximately 1.02.        -   Individual fruit weight.—208 g±31 g.        -   Rind.—Texture: Pitted. Color: RHS N25C (Orange). Thickness:            0.38 cm±0.08 cm to 0.47 cm±0.09 cm.        -   Adherence of mesocarp to endocarp.—Strong.        -   Attachment to stalk (strength).—Medium.        -   Albedo color.—RHS 10C (Yellow).        -   Albedo thickness.—0.2 cm to 0.5 cm.        -   Segments.—Quantity (per fruit): 10.4±0.8 to 10.4±0.87. Wall            thickness: Thin. Vesicle length: 1.07 cm±0.13 cm. Vesicle            width: 2.3 cm±0.07 cm.        -   Naval.—Absent.-   Seeds:    -   -   Quantity per fruit.—The original ‘N7-3’ tree yielded            approximately 0.17±0.42 seeds per fruit; the second            generation ‘N7-3’ trees yielded approximately 0.05 seeds per            fruit while standard ‘Valencia’ fruit averages approximately            3.9 seeds per fruit.        -   Surface appearance.—Wrinkled.        -   Seed coat color.—RHS 158B (Yellow-white).        -   Inner seed coat color.—RHS 165C (Greyed-orange).        -   Outer seed coat color.—RHS 161D (Greyed-yellow).        -   Chalazal end color.—RHS 165A (Greyed-orange).        -   Cotyledon color.—RHS 157D (Green-white).-   Reproductive organs:    -   -   Anther length.—Shorter than petals.        -   Anther color.—RHS 15B (Yellow-orange).        -   Stamen quantity.—23.7±2.9.        -   Stamens per petal.—Approximately 5.1.        -   Filaments.—Are fused.-   Juice Data: ‘N7-3’ has a later maturity date than standard    ‘Valencia’ trees, which is the latest available commercial variety    in Florida. Juice data from ‘N7-3’ fruit shows that ‘N7-3’ holds    good fruit quality into June by maintaining a higher fruit acid    level that keeps a brix/acid ratio in the preferred range of 15 to    18 (minimum legal ratio is 12). Additionally, the juice percentage    obtained from ‘N7-3’ fruit averages about 49% to 55.5%, increasing    with the age of the tree.

COMPARISON WITH PARENTAL AND KNOWN CULTIVARS

‘N7-3’ differs from the commercial comparison variety ‘Alvarina’ (U.S.Plant Pat. No. 19,575) in that ‘N7-3’ has smaller leaves (7.67 cm inlength and 4.61 cm in width) with acuminate apices, while ‘Alvarina’ haslarger leaves (10.0 cm to 12.0 cm in length and 8.0 cm to 10.0 cm inwidth) with generally cuspidate apices. Additionally, when compared to‘Alvarina’, the fruit and juice of ‘N7-3’ have a richer (deeper) orangecolor.

Table 1 shows comparative data of juice characteristics from ‘N7-3’ ascompared to the parental variety ‘Valencia’ (unpatented).

TABLE 1 Juice Data from ‘N7-3’ as compared to ‘Valencia’ (Location: CRECNorth-40 Grove, Lake Alfred, Florida, ‘Swingle’ citrumelo rootstock)Date Variety Brix Acid Ratio Lb solids Color May 14, ‘N7-3’ 12.18 0.7017.40 6.35 37.9 1998 ‘Valencia’ 13.44 0.57 23.58 7.21 37.7 Feb. 19,‘N7-3’ 11.43 1.16 9.85 6.54 36.9 1999 ‘Valencia’ 10.93 0.83 13.17 5.4436.8 Jun. 19, ‘N7-3’ 11.57 0.62 18.7 5.25 39.1 2000 ‘Valencia’ 12.810.51 25.1 6.44 39.0 May 15, ‘N7-3’ 10.82 0.79 13.7 4.98 37.9 2001‘Valencia’ 10.86 0.58 18.7 6.43 39.3 Mar. 14, ‘N7-3’ 11.72 0.91 12.886.32 37.8 2003 ‘Valencia’ 12.46 0.90 13.84 6.54 38.2 Feb. 28, ‘N7-3’12.30 1.33 9.25 6.11 n.d. 2006 ‘Valencia’ 12.69 1.15 11.03 6.67 n.d.Apr. 10, N7-3’ 11.86 0.80 14.83 6.00 39.2 2007 ‘Valencia’ 12.96 0.7517.28 6.71 39.9 *Juice quality data was obtained from the UF/CREC StateTest House Brix: is the percent of sucrose determined with a hydrometer.Acid: is the percent of citric acid determined by standard titration.Ratio is Brix/Acid Lb solids was calculated as pounds of soluble sugarsper 90 lb box of fruit. FDA legal juice color was measured used a GretagMacbeth Color-Eye 3100 spectrophotometer. The computer software that isused with this machine is PorPalette 5.2.1 Quality Control 2001. n.d =not determined

-   Resistance to insects, disease or pests: Typical of standard    ‘Valencia’ sweet orange trees.

1. A new and distinct cultivar of sweet orange tree as shown anddescribed herein.